Heat distribution system for tobacco curing barns



New. 16, 1954 J. A. MAUL ET AL HEAT DISTRIBUTION SYSTEM FOR TOBACCOCURING BARNS 2 Sheets-Sheet 1 Filed Sept. 27, 1950 all?! IIZIIQINVENTORS JOHN A. MAUL PHILIP KAFT L v HEAT DISTRIBUTION SYSTEM FORTOBACCO CURING- BARNS John A. Maul and Philip Kaftol, Brooklyn, N. Y.,assignors to American Machine and Foundry Company, a corporation of N ewJersey Application September 27, 1950, Serial No. 186,972. 8 Claims.(Cl. 26319) This invention relates to tobacco curing apparatus and moreparticularly to a heat distribution apparatuswhich is used with a jettype burner.

After harvesting tobacco leaves it is the practise to hang the leaves ina tobacco curing barn where they are dried and cured by means ofartificial-heat. Due to advancements made in the direct fired oilburning art, it has now become possible-to so completely oxidize thefuel that the combustion gases can be discharged directly into thetobaccocuring barn using'on'lyone burner without any danger ofcontaminating the tobacco leaves with carbon or oil smudge. This has theadvantage that less costly equipment is required to cure tobacco, fuelis more eificiently utilized and 'lessheat is dissipated to the outsideatmosphere.

Such a burner releases considerable heat and to be practical this heatmust be distributed in such a way that it can be effectively employed inthe curing barn without becoming a fire hazard.

it is therefore an object of this invent-ion to provide a distributionapparatus which is economical 'to'construct and which will stand upunder the maximum temperatures and thermal shock which are encountered.

Another object is to provide a material for a heat distributionapparatus which will have sufficient thermal insulation to lower thesurface temperature of the apparatus to such a degree that combustiblematerial such as tobacco leaves coming into contact withthedistrib'ution apparatus will not ignite.

it is also an object of the present invention toprovide an improved heatdistribution system which can be easily assembled in a tobacco barn andwhich permits the distribution apparatus to be readily packaged forshipment.

Another object of this invention is to provide amaterial out of whichdistributing ducts can be made-which is light in weight so as todecrease shippingcosts and which can withstand high temperatures whichare encountered in jet type burners.

Another object is to provide a heat distribution apparatus, the maincomponents of which are of similar construction and are adaptable fornesting together so that they can be easily packaged for shipment.

A further object is to provide heat distribution apparatus which willhave suflicient heat retaining ability to prevent short cycling of theburner;

Another object is to provide sufiicient mechanical strength in theapparatus so that it can withstand occasional abuse as it might receivein a tobacco barn.

Another object is to provide suificient flexibility in the system sothat the heat on one side of the barn can be readily increased ordecreased to compensate for. uneven distribution of tobacco in the barnas well as to effects attributable to weather andthe heat insulatingability provided by the walls of the barn itself.

Other objects and features of 'the invention will appear as thedescription of the particular physical embodiment selected to illustratethe invention progresses. In the accompanying drawings, which form apart of this specification, like characters of reference have beenapplied to corresponding parts throughout the several views which makeup the drawings.

Fig. 1 is an isometric view of the improved heat distributing apparatus,

Fig. 2 is a cross-sectional end elevation taken on the line 2-2 ofFigure 1 showing theheatdistributing header in cross-section,

States Patent Fig. 3 is a cross-sectional. end elevation of adistributing arm before clamping,

Fig.u4 is a cross-sectional end elevation taken on line l -4 of. Figurel of the same distributing arm showing the unit after clamping,

Fig. 5 is an isometric view of a modified form of the heat distributionapparatus.

The heat distributing apparatus shown in Figure 1 is well suited for usewith et type burners of the type having high temperatures such as thatshown and described in copending patent application Serial Number179,710, filed on August 16, 1950, by Henry A. Oldenkamp, now Patent2,673,726.

In the arrangement used to illustrate the invention the heatdistributing apparatus comprises a fire box or chamber C, a headerdesignated generally by the letter H and heat distributing arms A. Whilethis particular arrangement of the header and arms have been found to bevery satisfactory it is evident that in some installations it may bedesired to modify them by making the arrangement a modification of a U,I, X or O shape instead of the T- and L-shaped arrangement shown in thepresent embodiment.

The fire box or chamber C receives the hot combustion gases from the jetburner B. Since there is considerable heat in such combustion gases thischamber must be able to stand up under high operating temperatures. ithas been found that while fire brick and fire clay stand upsatisfactorily it is not always feasible to transport them for smalljobs. Vermiculite concrete on the other hand has been found byapplicants to be more readily adaptable for such use. This material canbe cast in sections which are readily transportable. They are alsorelatively light in weight and can stand up in transportation and useunder high temperatures Iand may be quickly assembled on the job into afire The header H comprises an inverted U-shaped tunnel made. up oftwosections 10 and 12 and a bottom section 30, as shown in cross section inFig. 2. Arms A extendoutwardly from the header H to distribute the hotcombustion gases received therefrom. The header H and the arms A arealso constructed of a suitable refractory material such as vermiculite.

While the exact ingredients of the vermiculite concrete may be vaned asdesired as in mixing sand, cement and cinders, it has been foundsatisfactory for example to use one 'partof cement and four parts ofvermiculite aggregate to make e sections of which the header H and armsA are made. In addition the concrete may, if desired, be aged or curedby artificial heat.

To assist in reinforcing each component section, suitable reinforcingmetal, such as expanded metal 14 may be mounted in each section as it ismade. Suitable anc hors 16 and 18' are placed in the vermiculite at thetime it is poured to provide projecting lugs 20 and 22 through which asuitable clamp 24 can be inserted to draw bothsections together at theirupper end. These is tightened it will cause the bottom of sections tospread out.

The bottom portion of the header H consists of a vermrculite plate 30.which has ridges 32 and 34 extending upwardly along each side upon whichthe upper section is designed to be supported. The bottom plate 30 mayalso be reinforced by suitable reinforcing iron 36, such as expandedsheet metal. At the time the vermiculite is cast or poured into theform, suitable lugs 38 and 40 are incorporated into the concrete so asto form projecting members 42 and 44 against which the two half shells10 and 12 can engage at their lower end, when the clamp bolt 24 istightened so as to spread apart the lower ends of the housing.-

A plurality of arms A extend at right angles from the header H. The armsA are connected to the header H by means of a suitable elbow joint L orT joint T. The arms are made up of two half sections of the same type ofmaterial as the headers 10 and 12. Since heat travels alongthetop ofthearms, it is possible to leave the bottom portion of the arms openwhere. the arms are horithe U-shaped Zontally arranged. The sections and12, making up the arms A are supported on suitable spaced rails 46 and48 such as angle iron. The angle irons 46 and 48 are joined together byspacing cross bars 50, and are supported in elevated position onsuitable supports 52 such as brick or cement blocks.

Each pair of half sections comprising the inverted U- shaped housingarms A are separated from each other lengthwise along the rails 46 and48. The distance each pair of half sections are separated from eachother are progressively increased as the distance from the header Hincreases. This permits heat to escape through the joints out into thetobacco barn uniformly across the entire barn. Where an unevendistribution of heat is desired so as to compensate for specialconditions such as wind, uneven loading of the barn, etc. the jointspacings can be increased. This will release more heat on this side ofthe barn than on the other side. It will thus be appreciated that thisheat distribution apparatus is highly adaptable to a drying conditionfound in different tobacco curing barns.

In some cases it may be desirable to assist the gases in passing fromthe header H through the distributing arms A by having the arm A mountedat an inclined angle from the header H. In this case the bottom portionof the arm is preferably maintained closed so as to confine the heattherein and to allow it to escape through the spaced joints between eachsection. This will result in an even distribution of hot gases along theentire length of the arm. This adaptation of the arm also increases thefiow of hot gases through the arm, thereby permitting this arrangementto also be used for compensating for varying conditions in the tobaccobarn.

A suitable wire netting or screen 54 is placed over each joint and atthe ends of the arms to assist in the dissipation of heat escapingthrough the joints and to prevent falling tobacco or other combustiblematerial from coming in contact with the hot gases.

The header H is supported on a similar pair of rails 56 which are spacedfrom each other by bars 58 in the same manner as is done by bars 50 tomaintain the rails 46 at a fixed distance with respect to each other.

The hot combustion gases are delivered from the jet type burner B,located on the outside of the tobacco curing barn, into the fire box C.The fire box or chamber C as previously stated is made of a suitablerefractory material to receive the hot gases from the burner B anddeliver them to the header H. As previously mentioned the fire box C canbe made of fire brick or a vermiculite concrete such as the header H anddistributing arms A are made of or a combination thereof. The type ofdirect fired burner referred to in this application may be similar indesign and construction to that shown and described in the copendingapplication Serial Number 179,710 previously referred to therein.

In the modified form of our invention we have disclosed how the heatdistribution system shown in Figure 5 may be made in the form of fiatblocks 76 consisting of a suitable heat resisting material such asvermiculite concrete. The blocks may be nailed together by nail 78 ormay be screwed together by suitable screws. By forming one side of theedge of the distributing arms with a slight taper it will cause thelower portion of the flat blocks to expand outwardly against the siderails 80 and 82, when the flat blocks are fastened together by nails orlag screws 78. As in the preferred form of the invention thedistributing arms are open at their bottom but the header is enclosed onall sides. Each joint of the distributing arm is slightly separated. Theamount of separation is varied depending on where heat is desired andgenerally the amount of separation is increased, the greater thedistance the joint is from the header.

In those cases where the distributing arms are mounted at an inclinedangle to facilitate hot gases moving therethrough the underportion ofthe arms are enclosed so as to prevent the hot gases from escapingtherefrom. The joints between the sections making up the distributingarms are separated however in the manner just described so as to permitthe hot gases to escape from the arms through these separations.

The operation of the heat distribution apparatus may be brieflydescribed as follows:

Fuel oil is delivered to the burner B from a suitable source (notshown). The burner B discharges the combustion gases into the fire box Cwhere they are completely oxidized and from where they escape into theheader H. The gases are pushed from the header H into the distributingarms A. -In moving through the distributing arms A the gases tend torise to the upper end of the inverted U-shaped arms. In passing fromsection to section a certain amount of gas escapes through each jointuntil at the end of the arms all the remaining gas escapes. Any fallingleaves will be kept out of dangerous contact with the hot gases by thescreens 54.

It will be noted that applicants apparatus enables a direct fired jetburner to be effectively used for curing tobacco because he has deviseda heat distributing arrangement which is capable of evenly distributingheat received from a single source at high temperatures across theentire bottom of the tobacco curing barn.

The present invention discloses how the cost of curing tobacco can bematerially reduced by utilizing all the heat of the combustion gases bypermitting them to be discharged into the tobacco curing barn directlyand providing a suitable type of material which will not melt ordeteriorate when subjected to the heat of a direct fired jet typeburner.

The present heat distribution system is of such practical design andconstruction that it can be readily shipped to farmers in the field atreasonable cost because of its lightness in weight and because it may bestored compactly for shipment. It is also sufiiciently rugged towithstand normal abuse such as individuals standing thereon.

Vermiculite concrete has been found to have such characteristics that itis capable of storing heat so that when the jet fired burner shuts offthe vermiculite heat distributing apparatus will continue to radiateheat into the tobacco barn and thereby decreasing the frequency ofoperation of the burner.

The invention above described may be varied in construction within thescope of the claims, for the particular device selected to illustratethe invention is but one of many possible embodiments of the same. Theinvention, therefore, is not to be restricted to the precise details ofthe structure shown and described.

What is claimed is:

1. A tobacco curing barn heat distributing apparatus for use with a jetfired burner comprising, a fire box made of refractory material forreceiving the hot combustion gases from the jet fired burner, ducts madeof a refractory material and connected to said fire box for leading thehot combustion gases away from said fire box, and distributing armsconnected to said ducts and extending transversely to said ducts, saidarms comprising a pair of rails fixed in a position above the floor anda plurality of substantially inverted U-shaped members of vermiculiteconcrete resting on said rails, each of said U-shaped members beingspaced from the adjacent U-shaped members to allow hot gases to passupwardly at spaced intervals along the arms, and each of said U-shapedmembers being made from a plurality of sections of vermiculite concrete.

2. A heat distributing apparatus for use with a jet fired burnercomprising a fire box made of refractory material into which hotcombustion gases from a jet burner are discharged, tubular members madeof a refractory material extending outwardly from said fire box fromwhich the hot combustion gases received from the fire box are conductedaway from the fire box, and heat distributlng arms connected to saidtubular members and extending substantially transversely from saidmembers, said arms comprising a pair of rails fixed in a position abovethe floor and a plurality of arm sections made from an assembly ofvermiculite concrete components connected to said tubular members andresting on said rails, each of said arms having a longitudinal openingformed along its lower length to conduct hot gases away from saidtubular members across the floor of a tobacco curing barn.

3. A- distribution system for use with a direct fired jet type burnercomprising a hollow header for receiving hot combustion gases from saidburner, distributing arms connected to said header and extendingtransversely with respect to said header, said arms having a pair ofrails fixed in a position above the floor and a plurality of invertedsubstantially U-shaped sections made up of two elongated walls ofvermiculite concrete joined together along their upper sides and havingthe lower portion of their length resting on said rails, each of saidU-shaped sections being spaced from the adjacent U- shaped section toallow hot gases to pass upwardly at spaced intervals along said arms.

4. In a tobacco curing barn, apparatus for distributing hot combustiongases received from a single source of supply, said apparatuscomprising, a combustion gas receiving chamber, ducts made ofvermiculite extending outwardly from said chamber for conducting hotcombustion gases away therefrom, angle iron supports positioned at rightangles to said ducts, sections of vermiculite supported on their edgeson said rails and having their opposite edges beveled so that when thebeveled edges are clamped together they cause the lower edge of eachsection to expand outwardly against said rails, said clamped sectionsbeing spaced from one another to allow gases being moved therethrough toescape through said spacings, and clamps for holding the upper edges ofsaid sections together.

5. A heat distribution system for a tobacco curing barn comprising afuel burner, a fire box made of refractory material for receiving thehot combustion gases from the burner, a header made of refractorymaterial and connected to the fire box for leading the hot combustiongases away from the fire box, angle irons extending sub stantiallytransversely from said header, elongated vermiculite duct sectionssupported along their elongated edges on said angle irons fordistributing the hot combustion gases received from said header acrossthe floor of a tobacco curing barn, each of said sections being madefrom a plurality of components and means for clamping the components ofsaid sections together to force the lower sides of said sectionsoutwardly against said rails, said vermiculite ducts being made ofsections spaced linearly from one another to permit heat to escapethrough said spacings, a source of hot combustion gases and meanscoacting with said vermiculite ducts for moving said hot combustiongases through said vermiculite ducts.

6. A heat distribution apparatus for use with an intermittently operatedfuel burner in a tobacco curing barn comprising a combustion chamberinto which said burner discharges hot combustion gases, ducts made ofrefractory material for conducting the hot combustion gases away fromsaid combustion chamber, arms made from sections of hollow reinforcedvermiculite concrete connected to said ducts for conducting gasesreceived therefrom across the floor of a tobacco curing barn, saidsections being of a thickness adequate to store heat absorbed from thecombustion gases and to radiate heat therefrom when hot combustion gasesare not delivered to said sections, and means for supporting thesegments making up said arms at separated distances from one another toallow hot combustion gases being conducted through said arms to escapethrough said separations.

A tobacco curing apparatus comprising a combustion chamber for receivinghot combustion gases, ducts extending outwardly from said combustionchamber, flat slabs of vermiculite concrete secured together along theiredges to form individual duct sections for conducting hot combustiongases across the floor of a tobacco curing barn, rails extendingtransversely from said ducts for supporting said individual ductsections at a distance spaced from the floor of a tobacco curing barn,said sections being spaced from one another to allow a portion of thehot combustion gases to escape through each of said spacings and meanscoacting with said duct sections for moving said hot combustion gasesthrough said ducts and duct sections.

8. Apparatus for distributing heat across the bottom of a tobacco barncomprising a main duct, spaced rails having upwardly extending flangespositioned across the floor of a tobacco barn and positionedtransversely with respect to said main duct, ducts consisting of pairsof elongated vermiculite sections of inverted substantially U-shapedcross-section supported along their edges on said rails, the adjoiningedges of said sections being oppositely beveled so that the lower edgesmove against said rails when the adjoining edges of said sections arebolted together, said sections being spaced lengthwise from one anotherto allow hot combustion gases to escape through said spacings and meansfor bolting the adjoining edges of said sections together,

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